Stripped O2 Sensor

Well went to try swapping out my O2 sensors and they all came out easy except down stream bank 2 the sensor stripped. No threads. Im not sure what size the threads are to tap it out. It doesnt seem like the catalytic converter threads are messed up but I dont know. Any ideas?

The thread size is 18mm x 1.50.You can get a replacement o2 sensor bung at certain auto parts stores,welding the bung in is required.

I'd try tapping new threads. Use alot of neverseize for the new one.

stevenf12801
Just went to Autozone and bought a combination 14mm and 18mm spark plug tap. The threads are the same as the 18mm. It was a pain tapping it was really a chase and probably meant more for aluminum. Either that or the thread are hardend by the extreme heat and quick coolin in rain or snow. Now I have to get another O2 sensor. Ill probably but 2 1 for each up stream and put the old upstream in the downstream positions. Hopefully the tap will work. Thanks

Why did you mess with the downstream O2 sensors anyway? Those do nothing for performance/economy. They only measure catalytic converter function.

Joel

rodeo02
Iam getting a P0420 code. Catalytic effiency below threhold bank one. Wiswind had a good idea to swap the 2 downstream sensors and find out if the code switched sides. If it did the converter would not be bad. I already had done a vacume test to try and verify and it worked well. I believe it probably is the o2 sensor because I had a intake manifold leak. Leaked antifreeze into the cylinder. The o2 sensor was green. There does'nt appear to be excessive back pressure. It idles well. I will order 2 new O2 sensors and install them in the upstream spots.

Ahh.. I didn't know about your P0402 situation. Yep, swapping O2 sensors is a good troubleshooting tactic for that if it applies. If those cats do have a lot of years/miles on them, the catalyst is probably long gone. Oh the nightmares of OBDII compliant vehicles! :banghead:

Joel

rodeo02
190K miles. I hope just the O2 is bad. I did find a muffler shop to change it for $100.00 plus the cat. The Cat is about $350. from Rock Auto. Im trying to see how long I can keep this going. Im the original owner and well maintained. Everything just seems to go at once. Power door lock switch, The driverside window stopped yesterday no warning. Its a challenge.

If it's a 1996 with 190K on it, those cats are shot. The precious metal internals have long since worn away. If your plans are to hang on to the van, I'd get a new Y-pipe cat assy. and not waste your time/money messing with the sensors. You will never get the proper delta between the upstream/downstream O2 sensors to make the PO402 stay away with your current cats.

Joel

rodeo02
Are there test to check the cats? I read about a vacume test. Check vacume at idle rev up slowly to about 2500 rpm and watch the vacume gauge the needle should not flutter and should see a short rise in vacume and back down again. Its checking for back pressure. I also read of a destuctive test where you drill a hole on either side of the cat and check temperature. Either way I have to order one new O2 sensor anyway. I may as well order 2 that way I can replace both upstream and put the old ones in the downstream position. If the code comes back I will replace the cat. I also have never replaced the exhaust. Its original. I hate to have a muffler shop do it because the pipes they replace it with wont last as long.

You won't have to replace the other parts of the exhaust.
The "Y" pipe connects to the "flex pipe" that is in front of the big square muffler.
Use something like an old coat hanger, or other wire, to loop under the front part of the flex pipe to support it......as if you let it dangle....it will damage the "flex" parts of the flex pipe.

It is worth the $100 to have a shop replace the "Y" pipe......I've done it....and it is NOT fun laying on your back under the vehicle doing that.
The Walker "direct fit" was a bit tight.....and is against the oil pan.
It seems to be fine......and that is after a couple of years with it.

I like the idea of installing the new oxygen sensors in the upstream position.
When I got the Walker unit.....I like the fact that NONE of the oxygen sensors mount directly into the catalytic convertors.....like one of the downstream ones did on my factory original.

The new sensors should come with the anti-seize compound already on the threads.

Use care to direct the oxygen sensor wiring away from the hot exhaust components.

wiswind
I know I dont have to replace it but the intermediate pipe is rattling and it sounds like there might be a small exhaust leak. Did you replace yours? You have close to the same mileage and similar driving conditions as in Illinois.

rodeo02
Are there test to check the cats? I read about a vacume test...

The only way to get an accurate read on cat function is through gas analysis or the proper delta between the fore & aft O2 sensors. You can get a rough idea through temperature measurement. A working cat will be hotter than the surrounding exhaust. A cat that is the same temp (or lower) that the surrounding exhaust is not working. Flow and vacuum testing is for a plugged cat. A cat can still be free flowing, but not work.

Joel

rodeo02
I passed emmisions test about 6 months ago. Is that an indication that the converter is working? Wouldnt I be getting a higher hydrocarbon reading if they were bad? I am familiar with just about every aspect of a car with the excetion of the cat. Most of my mechanical experience was on muscle cars of the 60s. (Pre cats)

I still have my original flex pipe on.....it started to rattle.....and I put a hose clamp on each flex section....and it has been fine for a couple of years....but I have a new Walker unit ready to put in if it gives me trouble.
I went to put the new one in....but it was super stuck to the fitting on the front of the muffler....so I decided to wait.......

wiswind

Ill let you know how the new O2s work. I should get them tomorrow. I ordered them from Team Ford in Las vegas along with a door lock switch and a relay for the fuel pump. They told me there was a seperate one for the fuel pump. I thought the only one was in the ccrm. Im getting a bucking or hesitation on acceleration. It just seems to have started. I dont know if its related to the oxygen sensors or cats. I should know tomorrow. I posted a question on Millenium Fords web site about it and the mechanic who answered said it could be the cat causing the hesitation also.

rodeo02 (http://www.automotiveforums.com/vbulletin/member.php?u=63960)
You might be right. I just did not want to spend another $450.00

I am not aware of any other relay on the '96.
At some point, they moved the relays into the power distribution box and did away with the CCRM.

My CCRM has been replaced 2 times.
1 time to solve an issue with radiator fans.......and it fixed that problem.
2nd time was this spring because the A/C compressor clutch would not stay engaged....and that solved that problem......this was after the evaporator coil was replaced due to a leak.....so the cycling may have caused the relay to go bad.
No problem with fuel pump so far..........

Don't forget to keep that fuel filter changed.....as if it gets dirty....it will cause the fuel pump to work harder......draw more current....which is harder on the relay as well as the pump.

Nice thing is......it is running really great.....and I hope it stays that way for a good while.

I did not see any change from replacing my upstream oxygen sensors....but at this mileage.....I felt that it was worth having new ones in there.
I had a green stain on one of the upstream sensors.

wiswind
What is your mileage like? I am getting about 14 mpg. That is before and after the intake manifold gasket change. I used to get 16 oto 18 around town and amuch as 24 on the highway. Thanks

I feel comfortable saying that I can get 21 MPG on the highway......city mileage is a tough one.....If you are driving around the Chicago area.....you get more stop in the stop and go than most of the people in the Milwaukee area.
If you have an "I-Pass" ( For those not familiar......this is Electronic Toll Collection.....you have a module and an account with pre-paid tolls.....same as E-Zpass and the new I-Zoom in Indiana....all of which are interchangable....so 1 will work on ALL the tollways and Toll Bridges across the country that use this system)......that can save you a bit of sitting time....especially with the new "Open Road Tolling" that is now in place in the Chicago area.
On the Tri-State Tollway....in the Chicago area....ETC is 1/2 the cash price.....add the fuel savings....and the lower stress level......

Our gasoline prices in the Milwaukee area have gone up over 40 cents in the past week.....so a bit of savings is a good thing.

I have had some "1 tank wonders" that get me excited.....but I average it out over a few tanks of gasolne....and it is hard to get more than 2 tanks of gasoline that is all freeway driving.

wiswind
I live in a suburb of chicago about 25 Miles away. Most of the cars travels is local. However it has seen alot of Mileage to Florida, once a year and up North near Eagle River. The Ipass has proved to be a much easier and more efficent way to go. It amazes me to see how many people fom Illinois still pay cash at twice the price.

My parts didnt show up today Im anxious to try the O2 sensors and see if it solves the Cat code. Either way those 2 sensors were still original so I dont feel bad replacing them. I just not thrilled with possibly having to replace the cat. Good news is I have been watching the over flow bottle and the level isnt dropping.:grinyes:

As a side note I have the third transmission in this van about 90,000 on this one and fluid changed once. It shifting hard not smooth at times. I am afraid to change the trans fluid in fear it will loosen something and cause it to go again. Could the TRS cause that rough shifting or am I looking at another trans soon in your opinion. These things were designed for a Taurus and the Windstar is probably 1000 pounds heavier. I have the trailer package but only towed a trailer locally. Thanks for your responces.

An update Team Ford sent be my parts today minus 1 oxygen sensor. I installed the O2 sensor and drove it for about a half hour at different speeds. It appears to idle better. The hesitation and bucking is almost gone. Time will tell. The other sensor will arrive tomorrow so both upstream will be new.

Wiwind are all 4 of your oxygen sensors the same? I have 2 different colored plugs and 2 different type of connection. The alignmen pins are in different locations. The 2 O2 sensors in the rear are after market and they have no alignment pins. I just broke the pins off on the one sensor and put it in the rear. The connection is the same. When I ordered them they didnt ask me upstream or downstream. All data only lists one. Any idea? Connectors in upstream are green same as new sensor connector. The rear are blue?

I don't remember connector colors.....I read that the sensors are the same from front to rear...the only difference being the length of the wires on them.
I have not tried to plug them in differently.
I have a picture posted of my "Y" pipe with the sensors on it.
One thing may be that they might have changed the connectors to prevent them from being plugged in wrong.....I had read that that has caused a few mechanics to pull their hair out trying to track that down....so FORD may have made that change to make repair easier.

Transmission shifting HARD can be caused by too much fluid pressure.
The pressure is regulated to provide the correct shift......and this could be leading up to a tranny problem
If it were my transmission, I would change the fluid and add a product called "AutoRX" that can be bought online.
This is a product that will help to clean varnish buildup from inside the transmission.
You put this product in, and drive about 1500 miles (follow the instructions), then change the fluid and filter.
I would do several complete fluid changes.....not just a pan drop.

I would also highly recommed that you verify radiator fan operation.
With the vehicle idling, parked, and the A/C ON, the radiator fans should be running all the time.
If not.....look into the radiator fan low speed dropping resistor.
I have pictures posted of the location of that part.
Radiator fan operation is a major factor in cooling the transmission.

Cooling and fresh fluid are critical to transmission life.

Also, when you change your fluid by the method shown in my pictures, you will be able to verify fluid flow through the coolers.
FORD issued a TSB regarding repeat transmission failures caused by clogged transmission coolers.
When a transmission fails, junk can get into the fluid....blocking the flow through the coolers.....causing the replacement transmission to overheat and fail.
The fluid does not flow through the filter until is has come BACK from the cooler line.

I live in Wisconsin and only use the Tri-State tollway a few times a year.
I have an I-Pass, and am happy with the simplicity....and the time saved.
I mentioned it because this is one way to reduce some major wear and tear on a vehicle, as well as reduce fuel consumption and driver fatigue.

I-Pass, I-Zoom (new this year for the Indiana Toll Road), and EZ-Pass are all interchangable. For passenger car use.....you only need 1 of these modules to work across all the toll roads and bridges of all these systems.
I-Pass works on all the EZ-Pass turnpikes (PA, NY, etc) and bridges (NYC), and the EZ-Pass modules work on the I-Pass system.
Another thing worth note. The I-Pass, I-Zoom, and (I think) the EZ-Pass system take care of a trailer AUTOMATICALLY. So you can use the Electronic Toll Collection (ETC) lanes, including the Open Road Tolling on the Tri-State Tollway while pulling a trailer.....no need to enter the "Manual" lanes.

The Ohio Turnpipe plans to install Electronic Toll Collection in 2009, according to their website.

Got the other oxygen sensor today and installed it. I then took it for a ride and got it to temperature. It idles rough in park smooth in drive. I am still getting some bucking and hesitation but not as bad. The weater is cooler though. It seemed to be worse on hot days. Ill have to drive it for ahwile more and see if the P0420 comes back.

Rodeo02
The rear converter seems to be running about 30 degrees hotter then the front. The temperature difference from inlet side to outlet side measured with a digital thermometer was about 50 degrees hotter on the outlet side. Ill drive it for ahwile and see if the code comes back. If it does then I know ill have to change the cat.

Drove about 100 miles today and no P0420. The bucking is still there and seems to be worse with the air on.

Wiswind
when the air is running you said the fansshould be running on high. Does that meen when the ac cycles off the fans should stop? Mine stay on for about 20 or 30 seconds after the ac cycles off. Is that about how it should work? Or is it supposed to run as long as the control is in the ac positioin.

Something else I just thought of. When I jacked up the van I left it running to check the temperature of the cats. That may have taken about 20 minutes. When I let it down it ran better with little hesitation and when I floored it it squeeled the tires. Im thinking more and more the cat could be my problem but no codes yet.

The fans should be running on LOW speed......when my low speed resistor was broken....my fans would cycle on and off at high speed.
They stay on whether the compressor is engaged or not.

For the rough runnig......I would put a can of Berryman's B-12 Chemtool into a tank of gasoline to clean up the fuel injectors.....just in case that is contributing to your problem.

wiswind
Im sorry wiswind I dont understand about the fan motors. The low speed shhould be on all the time and the high speed should be on when the ac is on whether or not the compressor is cycling or not?

No...
2 things cause the fans to come ON.

Engine Temperature above a certain level......the low speed fans come on......if the temperature still goes above yet a higher temperature, the high speed fans come on.

When I turn my A/C on.....and the vehicle is not moving above a certain minimum speed, the radiator fans come on at LOW speed....and STAY on while the A/C is selected...and the vehicle is not moving some minimum speed.
I don't know if mine still cycle to high speed or not....have not noticed.

Low speed fan operation has the low speed dropping resistor in the circuit.
This is in a ceramic body.....and is located behind the passenger side headlight....very slightly toward the center of the vehicle....mounted on top of the metal bumper. You can see it when you look down behind the headlight.

The PCM decides when to turn the fans on......and at what speed.
The PCM directly drives the fan control relays....which are located inside the CCRM (Constant Control Relay Module)......on the '96 year.....at some point in later years, they moved relays out of the CCRM into the power distribution box.

For quite some time I did not have low speed radiator fans....just high speed.
The cause was a broken radiator fan low speed dropping resistor.
I am wondering how many transmissions out there had their lives shortened by just this problem.....as this would have a big impact on transmission fluid cooling when idling in traffic.

Thanks thats another problem. Mine only cycle to high not that that in itself would be bad more air flow. However Im not sure when there running at other times. Ill replace the dropping resistor. It sounds like it could be the ccrm also if it is not staying on when the ac switch is in the on position. Thanks again.